021 — Destructive actions should be secondary

Sometimes people use interfaces automatically, without paying too much attention to the copies in the interface. Especially heavy users that only want to get things done as soon as possible, so they press Enter and accept all steps without thinking.

Destructive actions (those actions that cannot be undone) should be designed keeping in mind this automatic mode, to prevent losing things accidentally. We can call this mode defensive design.

In defensive design, the destructive actions should require some extra attention from the user. For example, let's see the following confirmation:

Here, the primary button is to delete the item. If the user press Enter, this item will be removed and there's no way to undo this action.

In a defensive design, the default action should be to keep the item:

Now the primary button is to maintain the item, so the worst thing that would happen to the user if pressing Enter without thinking about the consequences is to don't delete the item.